Method for coating articles by mold transfer

ABSTRACT

A method for coating hydrogel and silicone hydrogel articles, and articles made by the method, are provided in which the coating is first applied to the molding surface in which an article-forming material will be cured to form the article. The method permits the thickness and uniformity of the coating to be more easily controlled than in known coating methods.

FIELD OF THE INVENTION

This invention relates to coated articles including, without limitation,contact lenses. In particular, the invention relates to coated hydrogeland silicone-hydrogel articles formed by curing a reaction mixture ofarticle-forming material in a mold the molding surface of which has afilm of the coating.

BACKGROUND OF THE INVENTION

The use of hydrogels to form articles such as contact lenses is wellknown. It is further known to increase the oxygen permeability ofhydrogels by adding silicone-containing monomers to the hydrogelformulations to produce silicone hydrogels.

Typically, it is desirable to increase the surface wettability ofhydrogel and silicone hydrogel articles by coating the articles with ahydrophilic coating. Numerous hydrophilic coatings and methods for theirapplication are known. For example, it is known to apply a coating to asilicone hydrogel lens using gas plasma. This coating method isdisadvantageous in that it requires dehydration of the lens prior toapplication of the plasma treatment, which treatment must be carried outunder vacuum conditions.

Alternatively, it is known to use solution- or solvent-based coatings tocoat lenses. However, these coating methods, as does the plasmatreatment, add steps to the lens manufacturing process and also resultin the production of large quantities of waste. Further, application ofa solution-based coating uniformly over a lens surface requiresextremely precise process control.

Application of a coating onto a mold into which a lens material isdispensed also has been disclosed. However, this method has beensuccessfully demonstrated only with non-silicone hydrogel materials.Therefore a need exists for a coating method for coating hydrogel andsilicone hydrogel lenses that overcomes one or more of thesedisadvantages.

DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS

A method for coating hydrogel and silicone hydrogel articles, andarticles made by the method, are provided in which an uncured coating isfirst applied to the molding surface of a mold in which anarticle-forming material will be cured to form the article. Thus, thearticle is coated during the course of curing the material from which itis formed eliminating the need for additional processing steps aftercuring is completed. Additionally, the method permits the thickness anduniformity of the coating to be more easily controlled than in knowncoating methods. Finally, because the method does not rely on specificreaction chemistries for attachment of the coating to the lens, as doother known coating methods, any of a wide variety of coatings thatcannot be adequately achieved using known coating methods are madepossible.

The invention provides a method for coating articles the methodcomprising, consisting essentially of, and consisting of: a.) coating amolding surface of a mold or a mold half with a coating effective amountof a high molecular weight coating composition; b.) dispensing a mixturecomprising a hydrogel monomer, a silicone-containing hydrogel monomer,or a combination thereof into the mold or mold half; and c.) curingunder conditions suitable to form an article coated with the coatingcomposition.

The invention may be used to produce any of a wide variety of coatedarticles. Preferably, the invention is used to produce ophthalmic lensesincluding, without limitation, contact, intraocular, and onlay lenses.More preferably, the invention is used to produce contact lenses.

For purposes of the invention, by “molding surface” is meant a surfaceused to form a surface of an article. Typically, molded articles areformed within a mold or between two mold halves. The mold or mold halvesused to form an article have an inner surface, the molding surface, andan outer non-molding surface. One ordinarily skilled in the art willrecognize that the molding surface will be of the dimensions and surfacetype requisite for forming the desired molded article.

By “high molecular weight” is meant an average molecular weight (“Mw”)sufficiently high so as to avoid dissolution of the coating into themonomer mixture used. For purposes of the invention, preferably themolecular weight is determined using gel permeation chromatography(“GPC”) with a light scattering detector and a high sensitivityrefractive index detector, for example model PL-RI available fromPolymer Labs. The GPC is performed using a phenogel 5 μm linear columnequipped with a guard column of the same components and a solution of0.5 weight percent lithium bromide in dimethyl formamide as the eluent.Flow rates are 0.5 mL per minute with injection volumes from about 10 toabout 20 μL. The precise Mw used will depend upon the coating selectedand the monomer mixture used. In a preferred embodiment, the Mw of thecoating is greater than about 300 kD.

As an alternative, useful coating compositions have a viscosity of agreater than about 1 cP, preferably at least about 4 cP, at 25 degreescentigrade. For purposes of the invention, preferably the viscosity isdetermined by dissolving the monomer or polymer component in a suitablesolvent and measuring the viscosity at a shear rate of 40/s. Preferablyused, when the article forming material is a silicone hydrogel is 1.00weight percent in a 1:1 solvent mixture of ethanol:ethyl lactate orisopropanol:isopropyl lactate.

By “hydrogel monomer” is meant is a material that after curing andhydration is elastomeric and has a water content of about 20 weightpercent or more. By “silicone-containing hydrogel monomer” is meant ahydrogel monomer that contains one or more silicone groups.

For purposes of the invention, the term “monomer” refers to compoundshaving number average molecular weights less than about 700, that can bepolymerized, and to medium to high molecular weight compounds orpolymers, sometimes referred to as macromonomers or macromers, havingnumber average molecular weights greater than about 700, containingfunctional groups capable of further polymerization. The term monomerincludes monomers, macromonomers, macromers, and prepolymers.Prepolymers are partially polymerized monomers or monomers that arecapable of further polymerization.

In preferred embodiment, the invention provides a method for coatinghydrogel and silicone-containing hydrogel articles the methodcomprising, consisting essentially of, and consisting of: a.) coating amolding surface of a mold or a mold half with a coating effective amountof a high molecular weight hydrophilic coating composition; b.)dispensing a mixture comprising a hydrogel monomer, asilicone-containing hydrogel monomer, or a combination thereof into themold or mold half; and c.) curing under conditions suitable to form anarticle coated with the coating composition. For purposes of theinvention, by “hydrophilic” is meant a material that, when polymerized,exhibits an advancing dynamic contact angle of less than about 100degrees in physiological saline.

In a more preferred embodiment, the invention is used to producephysiologically compatible contact lenses and, thus, provides a methodfor coating contact lenses the method comprising, consisting essentiallyof, and consisting of: a.) coating a molding surface of a mold or a moldhalf with a coating effective amount of a high molecular weighthydrophilic coating composition; b.) dispensing a mixture comprising ahydrogel monomer, a silicone-containing hydrogel monomer, or acombination thereof into the mold or mold half; and c.) curing underconditions suitable to form a contact lens coated with the coatingcomposition, wherein the lens exhibits physiological compatibility.

By “physiologically compatibility” or “physiological compatible” ismeant that the lens exhibits clinical performance, in terms of on-eyewettability and resistance to surface deposits that is equal to orbetter than that of an etafilcon A lens. On-eye wettability isdetermined by measuring non-invasive, tear break-up time using a tearscope placed between a slit lamp microscope and a lens wearer's eye. Thelens wearer blinks and holds the eye open while the eye is viewedthrough the slit lamp, typically at a magnification of about 16 to 20×.The time between the blink and the first observed non-wetting of thelens surface is the non-invasive, tear break-up time. The non-invasivetear break-up time for the lenses of the invention are equal to orgreater than that of an etafilcon A lens or equal to or greater thanabout 5 to about 10 secs. Preferably, the lens of the invention exhibita non-invasive tear break-up time of about 7 to about 10 secs.

Surface deposition resistance is measured for both the front and backlens surfaces by scanning the entire lens on eye using a slit lamp witha magnification of about 16 to about 20× and a beam width and height setat approximately one-half of the corneal diameter, typically a width ofapproximately 2 mm and a beam height of approximately 6 mm. Deposits maybe appear as discrete deposits, such as jelly bumps, or as oily patchesor film and will move with the lens during blink or Josephson Push-Uptesting. No observable deposition is a grade 0; grade 1 is about 1 toabout 5 percent of the lens surface with deposition; grade 2 is about 6to about 15 percent with deposition; grade 3 is about 16 to about 25percent deposition and grade 4 is greater than about 26 percentdeposition. The surface deposition for the lenses of the invention areequal to or greater than that of an etafilcon A lens meaning that lessthan about 15% of a clinical population will have Grade 3 or higherdeposition after one week of wear.

Coating compositions useful in the invention may contain any of a widevariety of monomers and polymers known in the art. Preferred arepoly(vinyl alcohol), polyethylene oxide, poly(2-hydroxyethylmethacrylate), poly(methyl methacrylate), poly(acrylic acid),poly(methacrylic acid), poly(maleic acid), poly(itaconic acid),poly(acrylamide), poly(methacrylamide), poly(dimethylacrylamide),poly(glycerol methacrylate), polystyrene sulfonic acid, polysulfonatepolymers, poly(vinyl pyrrolidone), carboxymethylated polymers, such ascarboxymethylcellulose, polysaccharides, glucose amino glycans,polylactic acid, polyglycolic acid, block or random copolymers of theaforementioned, and the like, and mixtures thereof. Preferably,poly(2-hydroxyethyl methacrylate), poly(vinyl pyrrolidone), poly(acrylicacid), poly(methacrylic acid), poly(meth)acrylamide, or poly(acrylamide)is used. More preferably, poly(2-hydroxyethyl methacrylate) is used.

The coating composition may, and for spin coating purposes preferablydoes, include a low boiling point, or less than about 90° C., solventand a high boiling point, or greater than about 100° C., solvent.Suitable low boiling solvents include, without limitation, n-methylpyrrolidone, acetone, chloroform, and alcohols such as methanol,ethanol, isopropanol, tert-butanol, and the like. Useful high boilingsolvents include, without limitation, methyl-, ethyl-, and isopropyllactate, ethylene and (poly)ethylene glycol, propylene glycol, n-methylpyrrolidone, dimethyl formamide, tetrahydrogeraniol, 1-butanol,1-pentanol, 1-hexanol, 1-octanol, 3-methyl-3-pentanol,dimethyl-3-octanol, 3-methoxy-1-butanol, 1,2 and 1, 4-butanediol,1,3-hexanediol, water, and the like. Typically, the ratio of the low tothe high boiling solvent will be about 1:1 at room temperature.

Additionally, the coating composition may include, and preferablyincludes, at least one surfactant. Suitable surfactants include, withoutlimitation, anionic surfactants, such as carboxylic acid salts, sulfonicacid salts, sulfuric acid salts, phosphoric and polyphosphoric acidesters, cationic surfactants, such as long chain amines and their salts,diamines and polyamines and their salts, quartemary ammonium salts,amine oxides, nonionic surfactants, such as polyoxyethylenatedalkylphenols, alkyl phenol ethoxylates, polyoxyethylenated straightchain alcohols, polyethoxylated polyoxypropylene glycols,polyethoxylated polydimethylsiloxane copolymers, fluorinated alkaneethoxylate copolymers, and long chain carboxylic acid esters,zwitterionic surfactants, such as pH-sensitive and pH insensitivesurfactants, and the like, and combinations thereof The specific typeand amount of surfactants used will depend upon the other components ofthe coating composition and the molding surface used. Typically, greaterthan or equal to about 0.001 weight percent and less than or equal toabout 5 weight percent based on the total weight of the coatingcomposition will be used.

In a first step of the method of the invention, a coating effectiveamount of a suitable coating composition is coated onto the moldingsurface of a mold or mold half. Preferably, all exterior surfaces of thearticle are coated and, thus, preferably the entire or substantially theentire molding surfaces of both mold halves are coated. One ordinarilyskilled in the art will recognize that one of the mold half's moldingsurfaces may be coated with a coating different or the same as that usedon the other mold half s molding surface.

The thickness of the coating composition, when dry, on the moldingsurface of the mold must be such that an article with an acceptablesurface roughness results. In embodiments in which the article is acontact lens, preferably a peak-to-peak surface roughness of thehydrated lens is less than about 500 nm is desirable. Thus, by coatingeffective amount is meant an amount of the coating compositionsufficient to provide a dry film thickness of the coating composition onthe molding surface that will result in a hydrated article with anacceptable surface roughness and for contact lenses preferably ahydrated lens peak-to-peak surface roughness of less than about 500 nm.More preferably, for contact lens embodiments, the amount of coatingcomposition used is an amount sufficient to produce a dry film thicknessof at least about 5 nm and no more than about 70 nm, preferably at leastabout 5 nm and no more than about 50 nm, more preferably at least about20 nm and no more than about 40 nm.

The coating composition may be applied to the molding surface by anysuitable method including, without limitation, compression, swabbing,spray coating, ink jet printing, aerosolization, nebulization, dipcoating, spin coating, and the like and combinations thereof Preferably,spin coating is used. Also, preferably, the coating is dried, orrendered non-tacky, prior to introduction of the article formingmaterial into the mold. Drying may be carried out using any suitablemethod, but preferably is carried out at temperatures up to about theglass transition temperature (“Tg”) of the mold material in air or undervacuum followed by equilibration under a blanket of nitrogen at anytemperature up to about the Tg of the mold material. During the vacuumexposure process, cold traps or other filters preferably are used toprevent contamination of the mold.

In a spin coating method, the coating composition preferably has a lowersurface tension than that of the molding surface's surface energy. Morepreferably, the surface tension of the coating composition is greaterthan about 3 dynes/cm below that of the surface energy of the moldingsurface to which it is applied when measured at the coating applicationtemperature. Most preferably, the surface tension of the coatingcomposition is more than 8 dynes/cm below that of the surface energy ofthe molding surface.

In a preferred spin coating method for use in forming contact lenses,spin coating is used to deposit a coating of a dry thickness of about 5to about 70 nm onto a molding surface of a mold. If the surface tensionof the coating differs from the surface energy of the mold by greaterthan about 8 dynes/cm when measured at the coating applicationtemperature, a suitable spin profile is at least about 6,000 and no morethan about 8,000 RPM using at least about 2 and no more than about 20 μlof coating composition and spinning for at least about 3 sec. If thesurface tension difference is less than about 8 dynes/cm, the mold isspun up to at least about 3,000 and no more than about 5,000 RPM usingat least about 2 and no more than about 10 μl of coating composition andthen the mold is spun up to at least about 7,000 and more than about10,000 RPM for at least about 3 seconds prior to stopping.

Any excess coating accumulating at the mold edges must be removed andremoval may be carried out by any convenient method including, withoutlimitation, swabbing the excess, removing the excess using vacuum,solvent, washing or pressurized air jet. Preferably, the excess isremoved using an air jet. In using the air-jet, it is critical thatspinning is started prior to the jet being turned on and, preferably,the air jet pressure is equal to or greater than about 10 psi.

In the second step of the method of the invention, an article-formingmaterial that is a mixture comprising a hydrogel monomer, asilicone-containing hydrogel monomer, or combinations thereof isdispensed into the mold or mold half Useful hydrogel monomers are knownand include, without limitation, hydrophilic monomers, preferablyacrylic- or vinyl-containing. Hydrogel monomers that may be usedinclude, without limitation, polyoxyethylene polyols having one or moreof the terminal hydroxy groups replaced with a functional groupcontaining a polymerizable double bond. Suitable monomers include,without limitation, polyethylene glycol, ethoxylated alkyl glucoside andethoxylated bisphenol A reacted with one or more equivalents of anend-capping group such as isocyanatoethyl methacrylate, methacrylicanhydride, methacryloyl chloride, vinylbenzoyl chloride, or the like, toproduce a polyethylene polyol having one or more terminal polymerizableolefinic groups bonded to the polyethylene polyol through linkingmoieties such as carbamate or ester groups. Additional examples ofhydrogel monomers include, without limitation, hydrophilic vinylcarbonate or vinyl carbamate monomers as disclosed in U.S. Pat. No.5,070,215 and the hydrophilic oxazolone monomers as disclosed in U.S.Pat. No. 4,910,277, both references incorporated herein in theirentireties by reference.

The term “vinyl-type” or “vinyl-containing” monomers refer to monomerscontaining the vinyl grouping (—CH═CH₂) and are generally highlyreactive. Such hydrophilic vinyl-containing monomers are known topolymerize relatively easily. “Acrylic-type” or “acrylic-containing”monomers are those monomers containing the acrylic group: (CH₂═CRCOX)wherein R is H or CH₃, and X is O or N and which are known to polymerizereadily such as, without limitation, N,N-dimethyl acrylamide (DMA),2-hydroxyethyl methacrylate (HEMA), glycerol methacrylate,2-hydroxyethyl methacrylamide, polyethyleneglycol monomethacrylate,methacrylic acid and acrylic acid.

The preferred hydrogel monomers used to make the silicone-containinghydrogel useful in the invention may be either acrylic- orvinylic-containing and the monomers themselves may be crosslinkers.Useful vinylic-containing monomers include, without limitation, N-vinyllactams, such as N-vinyl pyrrolidone (“CNVP”), N-vinyl-N-methylacetamide, N-vinyl-N-ethyl acetamide, N-vinyl-N-ethyl formamide, andN-vinyl formamide with N-vinyl pyrrolidone being preferred.

Particularly useful silicone-containing hydrogel monomers include thosethat contains at least two [—Si—O—] repeating units. Preferably, thetotal Si and attached O are present in the silicone-containing monomerin an amount greater than about 20 weight percent, and more preferablygreater than about 30 weight percent of the total molecular weight ofthe silicone-containing monomer.

Preferred silicone-containing hydrogel monomers are of the following ofStructure I:

wherein R₅₁, is H or CH₃, q is 1, 2, or 3 and for each q, R₅₂, R₅₃ andR₅₄ are independently an alkyl or an aromatic, preferably ethyl, methyl,benzyl, phenyl, or a siloxane chain comprising from 1 to 100 repeatingSi—O units, p is 1 to 10, r=(3−q), X is O or NR₅₅, where R₅₅ is H or aalkyl group with 1 to 4 carbons, a is 0 or 1, and L is a divalentlinking group which preferably comprises from 2 to 5 carbons, which mayalso optionally comprise ether or hydroxyl groups, for example, apolyethylene glycol chain. Examples of such monomers include, withoutlimitation, methacryloxypropylbis(trimethylsiloxy)methylsilane,methacryloxypropyltris(trimethylsiloxy)methylsilane,methacryloxypropylpentamethyldisiloxane, and(3-methacryloxy-2-hydroxypropyloxy)propylbis(trimethylsiloxy)methylsilane.

It is more preferred to use linear mono-alkyl terminatedpolydimethylsiloxanes (“mPDMS”) such as those shown in the followingStructure II:

where b is a distribution having a most frequently occurring b value andthat b value is 0 to 100, preferably 8 to 10; R₅₈ is a group containinga free radical polymerizable ethylenically unsaturated moiety,preferably methacrylate, methacrylamide, styryl, N-vinyl amide, N-vinyllactams, vinyl carbonates, vinyl carbamates, maleate, or fumarate; eachR₅₉ is independently an alkyl, or aryl group, which may be furthersubstituted with alcohol, amine, ketone, carboxylic acid or ethergroups, preferably unsubstituted alkyl or aryl groups, more preferablymethyl; and R₆₀ is an alkyl, or aryl group, which may be furthersubstituted with alcohol, amine, ketone, carboxylic acid or ethergroups, preferably unsubstituted alkyl or aryl groups, preferably aC₁₋₁₀ aliphatic or aromatic group which may include hetero atoms, morepreferably C₃₋₈ alkyl groups, most preferably butyl.

Additional silicone-containing hydrogel monomers may be combined withthe silicone-containing hydrogel monomers of Stuctures I and II to formthe articles produced by the method of the invention. Any knownsilicone-containing hydrogel monomer useful for makingsilicone-containing hydrogels can be used in combination with thesilicone-containing hydrogel monomer of Structure I and II to form thearticles of this invention. Many silicone-containing hydrogel monomersuseful for this purpose are disclosed in U.S. Pat. No. 6,020,445incorporated herein in its entirety by reference. Useful additionalsilicone-containing hydrogel monomers combined with thesilicone-containing monomers of Structure I to form the siliconehydrogels of this invention are the hydroxyalkylamine-functionalsilicone-containing monomers disclosed in U.S. Pat. No. 5,962,548incorporated herein in its entirety by reference. The preferredsilicone-containing linear or branched hydroxyalkylamine-functionalmonomers comprising a block or random monomer of the followingstructure:

Structure IIIwherein:

-   where n and m each is a distribution having a most frequently    occurring n and m value, respectively and that n value is 0 to 500    and that m value is 0 to 500 and (n+m)=10 to 500 and more preferably    20 to 250; R₂, R₄, R₅, R₆ and R₇ are independently a alkyl, or aryl    group, which may be further substituted with alcohol, ester, amine,    ketone, carboxylic acid or ether groups, preferably unsubstituted    alkyl or aryl groups; and R₁, R₃ and R₈ are independently an alkyl,    or aryl group, which may be further substituted with an alcohol,    ester, amine, ketone, carboxylic acid or ether group, preferably    unsubstituted alkyl or aryl groups, or are the following    nitrogen-containing structure:

Structure IV

-   with the proviso that at least one of R₁, R₃, and R₈ are according    to Structure IV, wherein R₉ is a divalent alkyl group such as    —(CH₂)_(s)— where s is from 1 to 10, preferably 3 to 6 and most    preferably 3;-   R₁₀ and R₁₁ are independently H, a alkyl or aryl group which may be    further substituted with an alcohol, ester, amine, ketone,    carboxylic acid or ether group, or has the following structure:

Structure V

where R₁₄, is H, or a polymerizable group comprising acryloyl,methacryloyl, styryl, vinyl, allyl or N-vinyl lactam, preferably H ormethacryloyl; R₁₆ is either H, a alkyl or aryl group which can befurther substituted with alcohol, ester, amine, ketone, carboxylic acidor ether groups, or a polymerizable group comprising acrylate,methacrylate, styryl, vinyl, allyl or N-vinyl lactam, preferably alkylsubstituted with an alcohol or methacrylate; R₁₂, R₁₃ and R₁₅ areindependently H, an alkyl or aryl, which can be further substituted withalcohol, ester, amine, ketone, carboxylic acid or ether groups, or R₁₂and R₁₅, or R₁₅ and R₁₃ can be bonded together to form a ring structure,with the proviso that at least some of the Structure IV groups on themonomer comprises polymerizable groups. R₁₂, R₁₃ and R₁₅ are preferablyH.

In alternative embodiments, the silicone-containing hydrogel mixturesuseful in this invention, composed of the silicone-containing hydrogelmonomers of either or both Structure I and Structure II also may containhydrophilic monomers. The hydrophilic monomers optionally used can beany of the known hydrophilic monomers useful in making hydrogels.

The preferred hydrophilic monomers used to make the silicone-containinghydrogel monomers of this invention may be either acrylic- orvinyl-containing. Such monomers may themselves be used as crosslinkingagents. Hydrophilic vinyl-containing monomers that may be incorporatedinto the silicone-containing hydrogels of the present invention includemonomers such as N-vinyl lactams (e.g. NVP), N-vinyl-N-methyl acetamide,N-vinyl-N-ethyl acetamide, N-vinyl-N-ethyl formamide, N-vinyl formamide,with NVP being preferred.

Other hydrophilic monomers that can be employed in the invention includepolyoxyethylene polyols having one or more of the terminal hydroxylgroups replaced with a functional group containing a polymerizabledouble bond. Examples include polyethylene glycol, ethoxylated alkylglucoside, and ethoxylated bisphenol A reacted with one or more molarequivalents of an end-capping group such as isocyanatoethyl methacrylate(“IEM”), methacrylic anhydride, methacryloyl chloride, vinylbenzoylchloride, or the like, to produce a polyethylene polyol having one ormore terminal polymerizable olefinic groups bonded to the polyethylenepolyol through linking moieties such as carbamate or ester groups.

Still further examples are the hydrophilic vinyl carbonate or vinylcarbamate monomers disclosed in U.S. Pat. Nos. 5,070,215, and thehydrophilic oxazolone monomers disclosed in U.S. Pat. Nos. 4,910,277,both references incorporated herein in their entireties by reference.Other suitable hydrophilic monomers will be apparent to one skilled inthe art.

More preferred hydrophilic monomers which may be incorporated into thepolymer of the present invention include hydrophilic monomers such asN,N-dimethylacrylamide (“DMA”), 2-hydroxyethyl methacrylate (“HEMA”),glycerol methacrylate, 2-hydroxyethyl methacrylamide, NVP,polyethyleneglycol monomethacrylate, methacrylic acid and acrylic acidwith DMA being the most preferred.

Other monomers that can be present in the reaction mixture used to formthe hydrogel or silicone-containing hydrogel monomer mixtures useful inthis invention include ultra-violet absorbing monomers, reactive tints,pigments, and the like. Additional processing aids such as releaseagents or wetting agents can also be added to the reaction mixture.

A polymerization initiator preferably is included with the hydrogel orsilicone-containing hydrogel monomer mixture. An initiator also may beused in the coating composition, but is not preferred. The coatingcomposition and monomer mixture initiators may be the same or different.The polymerization initiators used may be visible light, thermal, anultraviolet initiators, or the like, or a combination thereof Theseinitiators are well known in the art and commercially available. Theinitiator may be used in catalytically effective amounts which is anamount sufficient to initiate the polymerization reaction desired.Generally, about 0.1 to about 2 parts by weight per 100 parts of thehydrogel or silicone hydrogel will be used.

The monomer mixture is dispensed into the coated mold. The hydrogel orsilicone-containing hydrogel monomer mixture may be dispensed into themold or mold half by any convenient means including, without limitation,pipetting, dispensing via syringe, pumping via automated or manual pump,and the like and combinations thereof. In the next step of theinvention, the hydrogel or silicone-containing hydrogel monomer mixtureis cured, or polymerized to form a coated article. Dwell time, or theelapsed time from which the monomer mixture is dispensed into the molduntil curing commences is critical because the coating composition issoluble in the hydrogel and silicone-containing hydrogel monomermixtures. Dwell time must be less than about 5 minutes and preferably isless than about 45 secs.

The curing additionally is carried out under conditions suitable forcuring the coated article to be formed. Suitable conditions will dependon a number of factors including, without limitation, the amount andtype of the coating composition and monomer mixture used, the article tobe formed, and the nature, i.e., visible light or heat, of the cureused. The determination of the precise conditions required are withinthe ability of one ordinarily skilled in the art.

Curing of the monomer mixture may be initiated using the appropriatechoice of heat, visible or ultraviolet light, or other means andpreferably is carried out in the presence of a polymerization initiator.For contact lens production, the preferred initiator is a 1:1 blend of1-hydroxycyclohexyl phenyl ketone and bis(2, 6-dimethoxybenzoyl)-2, 4,4-trimethylpentyl phosphine oxide and the preferred method ofpolymerization initiation is visible light. For some monomer reactionmixtures it is preferred to cure the reaction mixtures at temperaturesslightly above room temperature, such as 25-90° C., so as to preventphase separation of the components. In a particularly preferredembodiment for contact lens production, the reaction mixture is precuredat about 45° C. followed by through-curing at about 70° C.

The resulting article will be coated with the coating composition coatedonto the molding surface of the mold. After curing of the monomermixture and coating composition, the resulting article may be treatedwith a solvent to remove any diluent used or any traces of unreactedcomponents, and hydrate the polymer to form the hydrogel. For contactlenses, the solvent used may be water or an aqueous solution such asphysiological saline.

Alternatively, and depending on the solubility characteristics of thediluent used to make the lens and the solubility characteristics of anyresidual unpolymerized monomers, the solvent initially used may be anorganic liquid such as ethanol, methanol, isopropanol, mixtures thereof,or the like, or a mixture of one or more such organic liquids withwater, followed by extraction with pure water (or physiological saline)to produce a hydrogel or silicone hydrogel lens swollen with water.

In a preferred embodiment, a silicone-containing hydrogel lens is madeby dispensing into the mold or mold half, and subsequently curing, amacromer with a reaction mixture that include silicone-containingmonomers and hydrophilic monomers. This technique affords a high levelof control of the structure of the ultimate product.

The macromers may be, and preferably are, made by combining a/an(meth)acrylate and a silicone in the presence of a Group TransferPolymerization (“GTP”) catalyst. These macromers typically comprisecopolymers of various monomers. They may be formed in such a way thatthe monomers come together in distinct blocks, or in a generally randomdistribution. These macromers may furthermore be linear, branched, orstar shaped. Branched structures are formed for instance ifpolymethacrylates, or crosslinkable monomers such as3-(trimethylsiloxy)propyl methacrylate are included in the macromer.Initiators, reaction conditions, monomers, and catalysts that can beused to make GTP polymers are known, as for example described in“Group-Transfer Polymerization” by O. W. Webster, in Encyclopedia ofPolymer Science and Engineering Ed. (John Wiley & Sons) p. 580, 1987.These polymerizations are conducted under anhydrous conditions.Hydroxyl-functional monomers, like HEMA, can be incorporated as theirtrimethylsiloxy esters, with hydrolysis to form free hydroxyl groupafter polymerization. GTP offers the ability to assemble macromers withcontrol over molecular weight distribution and monomer distribution onthe chains. This macromer is then reacted with a reaction mixturecomprising predominantly polydimethylsiloxane (preferably, mPDMS), andhydrophilic monomers.

Preferred macromer components include mPDMS,3-methacryloxypropyltris(trimethylsiloxy)silane (“TRIS”), methylmethacrylate, HEMA, DMA, methacrylonitrile, ethyl methacrylate, butylmethacrylate, 2-hydroxypropyl-1-methacrylate, 2-hydroxyethylmethacrylamide and methacrylic acid. It is even more preferred that themacromer is made from a reaction mixture comprising HEMA, methylmethacrylate, TRIS, and mPDMS. It is most preferred that macromer ismade from a reaction mixture comprising, consisting essentially of, orconsisting of about 19.1 moles of the trimethylsilyl ether of HEMA,about 2.8 moles of methyl methacrylate, about 7.9 moles of TRIS, andabout 3.3 moles of mono-methacryloxypropyl terminated mono-butylterminated polydimethylsiloxane, and is completed by reacting theaforementioned material with about 2.0 moles per mole of3-isopropenyl-ω,ω-dimethylbenzyl isocyanate using dibutyltin dilaurateas a catalyst.

Silicone-containing hydrogels can be made by reacting blends ofmacromers, monomers, and other additives such as UV blockers, tints,internal wetting agents, and polymerization initiators. The reactivecomponents of these blends typically comprise a combination ofhydrophobic silicone with hydrophilic components. Because thesecomponents are often immiscible because of their differences inpolarity, it is particularly advantageous to incorporate a combinationof hydrophobic silicone monomers with hydrophilic monomers, especiallythose with hydroxyl groups, into the macromer. The macromer can thenserve to compatibilize the additional silicone and hydrophilic monomersthat are incorporated in the final reaction mixture. These blendstypically also contain diluents to further compatibilize and solubilizeall components. Preferably, the silicone based hydrogels are made byreacting the following monomer mix: macromer; an Si₈₋₁₀ monomethacryloxyterminated polydimethyl siloxane; and hydrophilic monomers together withminor amounts of additives and photoinitiators. It is more preferredthat the hydrogels are made by reacting macromer; an Si₈₋₁₀monomethacryloxy terminated polydimethyl siloxane; TRIS; DMA; HEMA; andtetraethyleneglycol dimethacrylate (“TEGDMA”). It is most preferred thatthe hydrogels are made from the reaction of (all amounts are calculatedas weight percent of the total weight of the combination) macromer(about 18%); an Si₈₋₁₀ monomethacryloxy terminated polydimethyl siloxane(about 28%); TRIS (about 14%); DMA (about 26%); HEMA (about 5%); TEGDMA(about 1%), polyvinylpyrrolidone (“PVP”) (about 5%); with the balancecomprising minor amounts of additives and photoinitiators, and that thereaction is conducted in the presence of 20% wt dimethyl-3-octanoldiluent.

The preferred range of the combined silicone-containing monomer ofStructure I and additional silicone-containing monomers, if present inthe reaction mixture, is at least about 5 to about 100 weight percent,more preferably at least about 10 and no more than about 90 weightpercent, and most preferably at least about 15 and no more than about 80weight percent of the reactive components in the reaction mixture. Thepreferred range of optional hydrophilic monomer if present in the aboveinvention is at least about 5 and no more than about 80 weight percent,more preferably at least about 10 and no more than about 60 weightpercent, and most preferably at least about 20 and no more than about 50weight percent of the reactive components in the reaction mixture. Thepreferred range of diluent is from about 0 to no more than about 70weight percent, more preferably about 0 to no more than about 50 weightpercent, and most preferably about 0 to no more than about 20 weightpercent of the total reaction mixture. The amount of diluent requiredvaries depending on the nature and relative amounts of the reactivecomponents.

In a preferred combination of reactive components at least about 10 andno more than about 60, more preferably at least about 15 and no morethan about 50 weight percent of the reactive components issilicone-containing monomer, at least about 20 and no more than about 50weight percent of the reactive components is silicone-containing monomerof Structure I, at least about 10 and no more than 50 percent of thereactive components is a hydrophilic monomer, more preferably DMA, atleast about about 0.1 and no more than about 1.0 percent of the reactivecomponents is a UV or preferably a visible light-active photoinitiatorand about 0 to no more than about 20 weight percent of the totalreaction mixture is a secondary or tertiary alcohol diluent, morepreferably a tertiary alcohol.

Mold materials useful in the invention are those that are unreactive tothe coating composition and monomer mixture used. Preferably moldmaterials are polyolefins, such as polypropylene, and cyclicpolyoelfins, such as those available under the tradename TOPAS®.

The invention may be further clarified by a consideration of thefollowing, non-limiting examples.

EXAMPLES

In the examples, the following abbreviations are used:

Blue-HEMA product of the base-promoted displacement of one chloride ofReactive Blue # 4 dye by hydroxyethyl methacrylate. CGI 1850 1:1 (wt)blend of 1-hydroxycyclohexyl phenyl ketone andbis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentyl phosphine oxide DMAN,N-dimethylacrylamide DOE-120 polyethylene glycol 120 methyl glucosedioleate EtOH ethanol HEMA 2-hydroxyethyl methacrylate IPA isopropanolmPDMS monomethacryloxypropyl terminated polydimethylsiloxane Norbloc2-(2′-hydroxy-5-methacrylyloxyethylphenyl)-2H- benzotriazole PVPpoly(N-vinyl pyrrolidone) TEGDMA tetraethyleneglycol dimethacrylateTBACB tetrabutyl ammonium-m-chlorobenzoate THF tetrahydrofuran TMI3-isopropenyl-α,α-dimethylbenzyl isocyanate TRIS3-methacryloxypropyltris (trimethylsiloxy) silane

Example 1

A predominantly poly-DMA (“pDMA”) pre-polymer of DMA:HEMA of n=70: n=4was made using Group Transfer Polymerization and functionalized with n=3 mole equivalents of TMI as follows. 40 g THF, tetrabutylammonium3-chlorobenzoate (TBACB, 1M solution n THF, 0.31 mL, 0.00031 moles),0.09 g bis(dimethylamino)-methylsilane, 0.7 g p-xylene and 20.23 g (0.1moles) 2-trimethylsiloxyethyl methacrylate were charged to a dry,three-necked flask under nitrogen. 4.36 g (0.025 moles)Methyltrimethylsilyl dimethylketene acetal were added to the mixturewhile stirring. The reaction was allowed to reach an exothermal peak andthen to cool to 24° C. The solution was diluted with 82 g THF and 173.5g (1.75 moles) DMA was fed through a 100 mL syringe over a two hourperiod. The exothermal increase was controlled to below 55° C. byreducing the feed rate of DMA and cooling the flask with ice. AdditionalTBACB (1M solution in THF, 0.94 mL, 0.00094 moles) diluted with 9 mL ofTHF was fed slowly during the reaction. 160 g dry THF were added to thesolution after the temperature was dropped back to 36° C. The reactionwas quenched with a mixture of 3.6 g deionized water, 6.40 g methanol,and 0.06 g dichloroacetic acid at 24° C. after 4 ½ hours of totalreaction time. The quenched solution was allowed to reflux at 65° C. for5 hours and then solvents were distilled off while toluene was addeduntil the vapor temperature reached 110.3° C. To the toluene solutionwas added a mixture of 15.1 g (0.08 moles) TMI and 0.98 g dibutyl tindilaurate and the mixture refluxed at 115° C. for 3 hours. The resultingsolution was allowed to cool and was then filtered through a membraneand the solvent evaporated off under vacuum at 30-45° C.

Two coating formulations were made by dissolving the pre-polymer intoIPA at 25 weight percent based on the total weight of the solution,along with 0.1 weight percent of DOE-120 surfactant. The coatings eachwere applied to the molding surfaces of complementary mold halves oflens molds made of TOPAS® 5013. Application of the coating was bycompression molding of approximately 3 μl of coating solution onto themolding surface with a silicone pad. For the front curve moldingsurface, the pad was brought into contact with the coating, dropped ontothe molding surface, compressed for approximately 0.5 sec., held for 1sec., and released over a period of approximately 2 sec. For the backcurve molding surface, the pad was dropped onto the molding surface,compressed and released over a period of approximately 0.5 sec. Thecoating was dried at room temperature for 30 min. Mean dry coatingthicknesses were estimated to vary between 1 and 2 μm based on thicknessmeasurements on flat TOPAS surfaces using Atomic Force Microscopy(“AFM”).

Lenses were cast using the molds by dispensing into the molds a siliconehydrogel lens material of the following formulation:

TABLE 1 Weight Percent Macromer 18.95 TRIS 14.74 DMA 27.37 MPDMS 29.47NORBLOC  2.11 CGI 1850  1.05 TEGDMA  1.05 HEMA  5.26 100 parts of theabove listed formulation were mixed with 20 parts of3,7-dimethyl-3-octanol diluent.Macromer Preparation

To a dry container housed in a dry box under nitrogen at ambienttemperature was added 30.0 g (0.277 mol) ofbis(dimethylamino)methylsilane, a solution of 13.75 ml of a 1M solutionof TBACB (386.0 g TBACB in 1000 ml dry THF), 61.39 g (0.578 mol) ofp-xylene, 154.28 g (1.541 mol) methyl methacrylate (1.4 equivalentsrelative to initiator), 1892.13 (9.352 mol) 2-(trimethylsiloxy)ethylmethacrylate (8.5 equivalents relative to initiator) and 4399.78 g(61.01 mol) of THF. To a dry, three-necked, round-bottomed flaskequipped with a thermocouple and condenser, all connected to a nitrogensource, was charged the above mixture prepared in the dry box.

The reaction mixture was cooled to 15° C. while stirring and purgingwith nitrogen. After the solution reaches 15° C., 191.75 g (1.100 mol)of 1 -trimethylsiloxy-1-methoxy-2-methylpropene (1 equivalent) wasinjected into the reaction vessel. The reaction was allowed to exothermto approximately 62° C. and then 30 ml of a 0.40 M solution of 154.4 gTBACB in 11 ml of dry THF was metered in throughout the remainder of thereaction. After the temperature of reaction reached 30° C. and themetering began, a solution of 467.56 g (2.311 mol)2-(trimethylsiloxy)ethyl methacrylate (2.1 equivalents relative to theinitiator), 3636.6. g (3.463 mol) n-butylmonomethacryloxypropyl-polydimethylsiloxane (3.2 equivalents relative tothe initiator), 3673.84 g (8.689 mol) TRIS (7.9 equivalents relative tothe initiator) and 20.0 g bis(dimethylamino)methylsilane was added.

The mixture was allowed to exotherm to approximately 38-42° C. and thenallowed to cool to 30° C. At that time, a solution of 10.0 g (0.076 mol)bis(dimethylamino)methylsilane, 154.26 g (1.541 mol) methyl methacrylate(1.4 equivalents relative to the initiator) and 1892.13 g (9.352 mol)2-trimethylsiloxy)ethyl methacrylate (8.5 equivalents relative to theinitiator) was added and the mixture again allowed to exotherm toapproximately 40° C. The reaction temperature dropped to approximately30° C. and 2 gallons of THF were added to decrease the viscosity. Asolution of 439.69 g water, 740.6 g methanol and 8.8 g (0.068 mol)dichloroacetic acid was added and the mixture refluxed for 4.5 hours tode-block the protecting groups on the HEMA. Volatiles were then removedand toluene added to aid in removal of the water until a vaportemperature of 110° C. was reached.

The reaction flask was maintained at approximately 110° C. and asolution of 443 g (2.201 mol) TMI and 5.7 g (0.010 mol) dibutyltindilaurate were added. The mixture was reacted until the isocyanate peakwas gone by IR. The toluene was evaporated under reduced pressure toyield an off-white, anhydrous, waxy reactive monomer. The macromer wasplaced into acetone at a weight basis of approximately 2:1 acetone tomacromer. After 24 hrs, water was added to precipitate out the macromerand the macromer 30 was filtered and dried using a vacuum oven between45 and 60° C. for 20-30 hrs.

The lens material was cured in the molds using visible light forapproximately 30 min. at 45° C. after which the lenses were demolded,leached using 100% IPA, and exchanged into fresh borate-buffered salinesolution. The time between dispensing the lens material into the moldsand the initiation of the cure, or the dwell time, was less than 5minutes in all cases.

Lens wettability was measured using dynamic contact angle as follows.Five samples of each lens type were prepared by cutting out a centerstrip approximately 5 mm in width and equilibrating the strip inborate-buffered saline solution for more than 30 min. Contact angles ofthe strips were determined using a Cahn DCA-315 micro-balance. Eachsample was cycled×4 in borate-buffered saline and the cycles wereaveraged to obtain the advancing and receding contact angles for eachlens. The contact angles of the 5 lenses were then averaged to obtainthe mean contact angle for the set.

The advancing contact angles for the lenses from the coated molds were65±4°. The advancing contact angle for the uncoated control was 99±8°.This demonstrates that the mold transfer coating dramatically improvedthe wettability of the silicone hydrogel lenses.

Examples 2 - 5

Random copolymers of DMA and HEMA (n=272 for DMA and n=23 for HEMA) wereprepared using free-radical polymerization as follows. HEMA (300 mg,2.31 mmole), DMA (29.7 g, 300 mmole), and 100 mg CGI 1850 were dissolvedin 120 mL of 3-methyl-3-pentanol. The mixture was degassed thoroughly byevacuating for 10 to 15 min., followed by purging with nitrogen. Theevacuating/purging was repeated 3 to 4 times and then the mixture wasplaced under a nitrogen environment and transferred to a crystallizingdish and covered with a watch glass. The mixture was exposed to visiblelight, Phillips TL20 W/03T bulbs, for a period of approximately 1 hr andthen the polymerization was terminated by exposing the system to oxygen.

The resulting polymer was precipitated by diluting the mixture withhexanes. Further purification was carried out by dissolving the polymerin acetone and re-precipitating with hexanes. The acetone/hexanessequence was repeated and the white polymer was washed thoroughly withhexanes and dried on a rotary evaporator with the product being cut intoseveral small pieces prior to completion of drying. The yield was 27.0 g(90%) of a white, foam-like product.

A portion of the above product was derivatized as its methacrylate usingthe following procedure. A three-necked, 50 mL, round bottomed flask washeat dried under vacuum, placed under nitrogen and charged with 10 mLTHF. Pyridine, 5 mL, was added to the flask, followed by 645 mg (7.5mmole) methacrylic acid. The system was cooled to below 5° C. and 1.026g (9 mmole) methanesulfonyl chloride was added to the solution in adrop-wise fashion over a period of 5 to 10 min. The mixture was stirredfor an additional 10 min while allowing it to warm to room temperature.

A 250 mL, three-necked flask was charged with 9 g HBEMA/DMA copolymerand 9 mg phenothiazine. The system was purged with nitrogen and 50 mL ofTHF was added to dissolve the compounds. The mixed anhydride solutionwas added to the flask via a syringe and the reaction mixture wasstirred overnight at ambient temperature.

The solution was filtered through a sintered glass funnel into 200 mL ofstirred hexanes. The solvents were decanted and the product was purifiedby dissolving it in isopropyl acetate, followed by the addition ofhexanes. The polymer was washed with 2×50 mL of hexanes and dried in arotary evaporator. Further purification was required due to the highmethacrylic acid content. The product was dissolved in acetone, followedby precipitation using hexanes.

A coating formulation of 20 wt percent pDMA/HEMA and 0.1 wt percentDOE-120 in IPA was applied to TOPAS 5013 molds as in Example 1. Drycoating thickness was greater than 1 μm as measured by AFM. Both thenative polymer and functionalized (with methacrylate) were examined ascoatings. Lenses were made using the silicone hydrogel lens material ofExample 1, except that the dwell time was as set forth on Table 2 below.Additionally on Table 2 is shown the wettability for the coatings.

TABLE 2 Advancing Methacrylate Contact Angle Example Capping Dwell Time(°) 2 Yes  12 min. 87 3 Yes 2.5 min. 58 4 Yes  45 sec. 62 5 No  45 sec.82The results demonstrate that acceptable wettability, or an advancingcontact angle less than 90°, can be obtained with or without themethacrylate group. Further, the results show that contact angle isdependent on dwell time, times of less than 2.5 min. producing the mostwettable lens.

Examples 6-9

Poly-HEMA coatings were evaluated for efficacy and wettability. Thecoatings were prepared by exposing a solution of HEMA, Blue HEMA, andIRGACURE 1850 in ethylene glycol to low intensity visible light,Phillips TL20 W/03T bulbs, using curing times ranging from 1 to 2 hours.The polymers were isolated after aqueous work-ups followed by severalaqueous washes to remove unreacted components. Polymer molecular weightsof less than about 300 kD were found to be inadequate for use as acoating polymer with the lens material of Example 1. A poly-HEMA of 360kD MW, available from Aldrich Chemical Company, was successfully used asa coating. Coating formulations with differing concentrations ofpoly-HEMA were prepared as follows:

-   Poly-HEMA:water:ethanol:DOE-120=10:20:70:0.1 w/w-   Poly-HEMA:water:ethanol:DOE-120=15:20:65:0.1 w/w-   Poly-HEMA:water:ethanol:DOE-120=20:20:60:0.1 w/w

The coatings were applied to the molding surfaces of TOPAS 5013 moldsaccording to the procedure of Example 1, except that prior to coating,the molds were treated for <0.5 sec. with an air plasma to improvespreading of the coating solution onto the mold. Lenses were made usingprocedures and the silicone hydrogel lens material of Example 1, exceptthat dwell time was 45 sec.

The resulting coated lenses were tested for wettability using dynamiccontact angle and for surface roughness using AFM. AFM images wereacquired with contact mode AFM using a 0.06 N/m SiN₄ cantilever imagingin borate-buffered saline solution. Imaging was minimized before datawas acquired and typically was <10 nN. Images were of 20×20 μm, withinthe optical zone and on the anterior surface of each lens. Two lenseswere evaluated for a total of 6 images. Mean peak-to-peak roughnessvalues were calculated using 24 10×10 μm areas from these images.Peak-to-peak roughness was defined as the difference in height betweenthe lowest and the highest point in the area tested. On Table 3 is shownthe results.

TABLE 3 Poly-HEMA Advancing Mean Peak-to- in Coating Contact Angle PeakRoughness Example (%) (°) (nm) 6  0 107  <100 7 10 65 1425 8 15 46 32769 20 48 N/AThe results demonstrate that wettability improved with increasing levelsof poly-HEMA in the coating solution. Additionally, surface roughnessincreased with increasing poly-HEMA content with the 20 wt percentpoly-HEMA lens being too rough and misshapen to analyze. The 10 wtpercent poly-HEMA coating produced a dry coating thickness on the moldof approximately 200 nm. Target peak-to-peak roughness for a useful lensis<500 nm and, thus, the dry coating thickness must be substantiallyless than 200 nm to achieve an acceptable surface roughness whilemaintaining desired wettability.

Examples 10-13

The silicone hydrogel lens material of Example 1 produced lenses with awater content of approximately 31 percent. Another similar lensformulation, with a water content of 39%, is as follows:

TABLE 4 Weight Percent MACROMER 18 TRIS 14 DMA 26 MPDMS 28 TEGDMA  1HEMA  5 PVP  5 Norblock  2 CGI 1850  1The remainder of the formulation was additives and diluents. The monomerto diluent ratio was 100:20, the diluent being 3, 7-dimethyl-3-octanol.The lenses of this material were coated with the 300 kD poly-HEMAcoating, but resulting wettability and surface roughness wereunacceptable.

A higher Mw poly-HEMA, containing greater than 1.6 wt percent of BlueHEMA was synthesized using visible light initiated by CGI 1850 and theresultant polymer had a Mw of >1,000,000. A mixture of 900 mg blue HEMA,44.1 g HEMA, 615 mg CGI 1850 and 150 mL ethylene glycol was stirreduntil homogeneous and the system was degassed as described in Examples2-5. The mixture was transferred to a large crystallizing dish andcovered with a watch glass. Polymerization of the olefinic moieties wasconducted under visible light for approximately 1 hour. Upon quenchingof the polymerization using oxygen, the mixture was poured into 500 mLborate-buffered saline solution and stirred for several hours until thematerial was transformed into a more rigid form. The liquids weredecanted and the product washed with another 500 mL borate-bufferedsaline solution. The polymer was cut into several smaller pieces andstirred in 500 mL deionized water for more than 1 hour to the point thatthe product becomes gel-like and was sparingly soluble in the solvent.The mixture was then diluted with a small quantity of borate-bufferedsaline solution to enable better precipitation of the polymer. Themixture was filtered and washed in deionized water until the materialdid not appear soluble. The suspension was filtered, dried in a rotaryevaporator, cut into smaller pieces and further dried until it appearedcrystalline and anhydrous. The dark blue polymer was then milled intofine particles and subjected to more deionized water washingsaccompanied by 1 to 2 hours of stirring with each wash. Washingcontinued until little or no blue color was visible in solution and theproduct was filtered, dried at reduced pressure, and ground in ablender. The Mw of this coating polymer was measured to be 1.2 milliong/mol using GPC and a 2% solution of the polymer in a 1:1 ethanol:ethyllactate solvent had a viscosity of 17.7 cP at 25° C. at a shear rate of40/s.

This coating was used to coat TOPAS 5013 molds via spin coatingaccording to the following procedure. Solutions of the polymer from 0.5to 2 wt percent by steps if 0.5 wt percent were dissolved in a mixedsolvent system of 1 part ETOH and 1 part ethyl lactate. The coating wasapplied to the 20 molding surface of the mold by dispensing the solutiononto the center of a part spinning at approximately 6000 rpm andallowing the part to spin for 5 sec. before stopping. Lenses were madewith these coated molds using the above-described lens material and adwell time of 30 sec. On Table 5 is shown the wettability and surfaceroughness of the resulting lenses.

TABLE 5 Mean Peak- Poly-HEMA Advancing Dry Film to-Peak in CoatingContact Thickness Roughness Example (%) Angle (°) (nm)* (nm) 10 0.5 100 21 113 11 1.0 81 67 401 12 1.5 72 78 790 13 2.0 78 125  1170  *Measuredwith AFM on TOPAS flats.The results show that changing the dry film thickness can simultaneouslyachieve acceptable wettability and surface roughness.

Example 14

High Mw blue poly-HEMA coated silicone hydrogel lenses with theformulation listed on Table 6 were formed.

TABLE 6 Weight Percent Macromer 17.98  TRIS 14.00  DMA 26.00  MPDMS28.00  TEGDMA 1.00 HEMA 5.00 PVP 5.00 NORBLOC 2.00 Blue HEMA 0.02 CGI1850 1.00The remainder of the formulation were additives and diluents. Themonomer to diluent ratio was 100:20, the diluent being3,7-dimethyl-3-octanol. Acetic acid, 1% of the final mix, was used tostabilize the monomer.

TOPAS 5013 front and back curve molds were coated with a 1.25 wt percentsolution of blue-poly-HEMA and lens made as described in Examples 10-13.Excess coating accumulated near the edge of the front surface mold wasremoved using a cloth swab during the spinning process.

The lenses were tested for wettability and surface roughness prior toclinical evaluation. Mean peak-to-peak front surface roughness was 291nm and mean advancing contact angle was 83°. Five lenses of −0.50diopter power were fit in a contra-lateral study for a 30 min. wearschedule. The lens surface was equivalent in on-eye wettability, or tearbreak-up time, and deposition resistance to ACUVUE® etafilcon A lensesdemonstrating that application of the coating to the lens results in aphysiological compatible lens.

1. A method for manufacturing an article comprising the steps of: a.)coating a molding surface of a mold or a mold half with a coatingeffective amount of a high molecular weight coating composition having amolecular weight of greater than about 300 kD and comprising at leastone polymer selected from the group consisting of poly(vinyl alcohol),polyethylene oxide, poly(2-hydroxyethyl methacrylate), poly(acrylicacid), poly(methacrylic acid), poly(maleic acid), poly(itaconic acid),poly(acrylamide), poly(dimethylacrylamide), carboxymethylated polymers,polystyrene sulfonic acid, polysulfonate polymers, polysaccharides,glucose amino glycans, block or random copolymers thereof, or mixturesthereof; b.) dispensing a monomer mixture comprising, asilicone-containing hydrogel monomer, into the mold or mold half; andc.) curing the monomer mixture and the coating composition using a dwelltime of less than about 45 seconds and under conditions suitable to forman article coated with the coating composition; wherein said at leastone polymer does not chemically attach to the article.
 2. The method ofclaim 1, wherein the article is a contact lens.
 3. The method of claim 1or 2, wherein the monomer mixture further comprises at least onehydrogel monomer.
 4. The method of claim 1, wherein the coatingcomposition further comprises a low boiling point solvent and a highboiling point solvent.
 5. The method of claim 4, wherein the coating ofthe molding surface is carried out by spin coating.
 6. The method ofclaim 5, wherein spin coating is carried out using at least about 2 μland no more than about 20 μl of the coating composition.
 7. The methodof claim 6, further comprising applying, subsequent to the spin coatingstep, a pressurized air jet to an edge of the mold.
 8. The method ofclaim 1 wherein the coating composition has a viscosity of about 17.7 cPat 25° C.
 9. The method of claim 1 wherein the coating composition has aviscosity of at least about 4 cP at 25° C.
 10. The method of claim 1wherein the coating composition has a viscosity of greater than about 1cP at 25° C.
 11. The method of claim 4 wherein the low boiling pointsolvent comprises ethanol and the high boiling point solvent comprisesethyl lactate.
 12. The method of claim 4 wherein the low boiling pointsolvent has a boiling point of less than about 90° C.
 13. The method ofclaim 4 wherein the low boiling point solvent comprises ethanol.
 14. Themethod of claim 4 wherein the low boiling point solvent is selected fromthe group consisting of n-methyl pyrrolidone, acetone, chloroform,methanol, ethanol, isopropanol, tert-butanol and combinations thereof.15. The method of claim 4 wherein the high boiling point has a boilingpoint of greater than about 100° C.
 16. The method of claim 4 whereinthe high boiling point solvent comprises ethyl lactate.
 17. The methodof claim 4 wherein the high boiling point solvent is selected from thegroup consisting of methyl lactate, ethyl lactate, isopropyl lactate,ethylene glycol, polyethylene glycol, propylene glycol, dimethylformamide, tetrahydrogeraniol, 1-butanol, 1-pentanol, 1-hexanol,1-octanol, 3-methyl-3-pentanol, dimethyl-3-octanol, 3-methoxy-1-butanol,1,2-butanediol, 1,4-butanediol, 1,3-hexanediol, water and combinationsthereof.
 18. The method of claim 4 wherein the low boiling point solventand the high boiling point solvent are present at a ratio of about 1:1.19. The method of claim 11 wherein the low boiling point solvent and thehigh boiling point solvent are present at a ratio of about 1:1.
 20. Amethod for manufacturing an article comprising: a.) coating a moldingsurface of a mold or a mold half with a coating effective amount of ahigh molecular weight hydrophilic coating composition having a molecularweight of greater than about 300 kD and comprising poly(2-hydroxyethylmethacrylate).; b.) dispensing a monomer mixture comprising a hydrogelmonomer, silicone-containing hydrogel monomer, or combination thereofinto the mold or mold half; and c.) curing the monomer mixture andcoating composition using a dwell time of less than about 45 seconds andunder conditions suitable to form an article coated with the coatingcomposition wherein said coating composition does not chemically attachto the article.
 21. The method of claim 20, wherein the article is acontact lens.
 22. The method of claim 21, wherein the monomer mixturecomprises a hydrogel monomer.
 23. The method of claim 21, wherein themonomer mixture comprises a silicone hydrogel monomer.
 24. The method ofclaim 23, wherein the silicone hydrogel monomer mixture comprises areaction product of a silicone based macromer Group TransferPolymerization product and a polymerizable mixture comprising Si₈₋₁₀monomethacryloxy terminated polydimethyl siloxane, polydimethylsiloxaneother than Si₈₋₁₀ monomethacryloxy terminated polydimethyl siloxane, anda hydrophilic monomer.
 25. The method of claim 24, wherein the siliconehydrogel monomer mixture comprises the macromer in an amount of about 15to about 25 wt percent, the Si₈₋₁₀ monomethacryloxy terminatedpolydimethyl siloxane in an amount of about 20 to about 30 wt percent;methacryloxypropyl tris(trimethyl siloxy) silane in an amount of about15 to about 25 wt percent; N,N-dimethyl acrylamide in an amount of about20 to about 30 wt percent; 2-hydroxy ethyl methacrylate in an amount ofabout 2 to about 7 wt percent; tetraethyleneglycol dimethacrylate in anamount of about 0 to about 5 wt percent and poly(N-vinyl pyrrolidinone)in an amount of about 0 to about 5 weight percent.
 26. The method ofclaim 21, wherein the coating composition further comprises a lowboiling point solvent and a high boiling point solvent.
 27. The methodof claim 26, wherein the coating of the molding surface is carried outby spin coating.
 28. The method of claim 27, wherein spin coating iscarried out using at least about 2 μl and no more than about 20 μl ofthe coating composition.
 29. The method of claim 28, further comprisingapplying, subsequent to the spin coating step, a pressurized air jet toan edge of the mold.
 30. The method of claim 20 wherein the coatingcomposition has a viscosity of about 17.7 cP at 25° C.
 31. The method ofclaim 20 wherein the coating composition has a viscosity of at leastabout 4 cP at 25° C.
 32. The method of claim 20 wherein the coatingcomposition has a viscosity of greater than about 1 cP at 25° C.
 33. Themethod of claim 26 wherein the low boiling point solvent comprisesethanol and the high boiling point solvent comprises ethyl lactate. 34.The method of claim 26 wherein the low boiling point solvent has aboiling point of less than about 90° C.
 35. The method of claim 26wherein the low boiling point solvent comprises ethanol.
 36. The methodof claim 26 wherein the low boiling point solvent is selected from thegroup consisting of n-methyl pyrrolidone, acetone, chloroform, methanol,ethanol, isopropanol, tert-butanol and combinations thereof.
 37. Themethod of claim 26 wherein the high boiling point has a boiling point ofgreater than about 100° C.
 38. The method of claim 26 wherein the highboiling point solvent comprises ethyl lactate.
 39. The method of claim26 wherein the high boiling point solvent is selected from the groupconsisting of methyl lactate, ethyl lactate, isopropyl lactate, ethyleneglycol, polyethylene glycol, propylene glycol, dimethyl formamide,tetrahydrogeraniol, 1-butanol, 1-pentaol, 1-hexanol, 1-octanol,3-methyl-3-pentanol, dimethyl-3-octanol, 3-methoxy-1-butanol,1,2-butanediol, 1,4-butanediol, 1,3-hexanediol, water and combinationsthereof.
 40. The method of claim 26 wherein the low boiling pointsolvent and the high boiling point solvent are present at a ratio ofabout 1:1.
 41. The method of claim 33 wherein the low boiling pointsolvent and the high boiling point solvent are present at a ratio ofabout 1:1.
 42. A method for manufacturing contact lenses comprising: a.)coating a molding surface of a mold or a mold half with a coatingeffective amount of a hydrophilic coating composition having a molecularweight of greater than about 300 kD; b.) dispensing a mixture comprisinga silicone-containing hydrogel monomer into the mold or mold half; andc.) curing the mixture and coating composition using a dwell time ofless than about 45 seconds and under conditions suitable to form acontact lens coated with the coating composition, wherein the formedlens exhibits physiological compatibility and said coating compositiondoes not chemically attach to the article.
 43. The method of claim 42,wherein the mixture further comprises at least one hydrogel monomer. 44.The method of claim 42, wherein the silicone hydrogel monomer mixturecomprises a reaction product of a silicone based macromer Group TransferPolymerization product and a polymerizable mixture comprising Si₈₋₁₀monomethacryloxy terminated polydimethyl siloxane, polydimethylsiloxaneother than Si₈₋₁₀ monomethacryloxy terminated polydimethyl siloxane, anda hydrophilic monomer.
 45. The method of claim 44, wherein the siliconehydrogel monomer mixture comprises the macromer an amount of about 15 toabout 25 wt percent, the Si₈₋₁₀ monomethacryloxy terminated polydimethylsiloxane in an amount of about 20 to about 30 wt percent;methacryloxypropyl tris(trimethyl siloxy) silane in an amount of about15 to about 25 wt percent; N,N-dimethyl acrylamide in an amount of about20 to about 30 wt percent; 2-hydroxy ethyl methacrylate in an amount ofabout 2 to about 7 wt percent; tetraethyleneglycol dimethacrylate in anamount of about 0 to about 5 wt percent and poly(N-vinyl pyrrolidinone)in an amount of about 0 to about 5 weight percent.
 46. The method ofclaim 42, 43, 44, or 45, wherein the coating composition comprisespoly(vinyl alcohol), polyethylene oxide, poly(2-hydroxyethylmethacrylate), poly(acrylic acid), poly(methacrylic acid), poly(maleicacid), poly(itaconic acid), poly(acrylamide), poly(dimethacrylamide),carboxymethylated polymers, polystyrene sulfonic acid, polysulfonatepolymers, polysaccharides, glucose amino glycans, block or randomcopolymers thereof, or mixtures thereof.
 47. The method of claim 46,wherein the coating composition comprises poly(2-hydroxyethylmethacrylate).
 48. The method of claim 46, wherein the coatingcomposition further comprises a low boiling point solvent and a highboiling point solvent.
 49. The method of claim 48, wherein the coatingof the molding surface is carried out by spin coating.
 50. The method ofclaim 49, wherein spin coating is carried out using at least about 2 μland no more than about 20 μl of the coating composition.
 51. The methodof claim 50, further comprising applying, subsequent to the spin coatingstep, a pressurized air jet to an edge of the mold.
 52. The method ofclaim 42 wherein the coating composition has a viscosity of about 17.7cP at 25° C.
 53. The method of claim 42 wherein the coating compositionhas a viscosity of at least about 4 cP at 25° C.
 54. The method of claim42 wherein the coating composition has a viscosity of greater than about1 cP at 25° C.
 55. The method of claim 48 wherein the low boiling pointsolvent comprises ethanol and the high boiling point solvent comprisesethyl lactate.
 56. The method of claim 48 wherein the low boiling pointsolvent has a boiling point of less than about 90° C.
 57. The method ofclaim 48 wherein the low boiling point solvent comprises ethanol. 58.The method of claim 48 wherein the low boiling point solvent is selectedfrom the group consisting of n-methyl pyrrolidone, acetone, chloroform,methanol, ethanol, isopropanol, tert-butanol and combinations thereof.59. The method of claim 48 wherein the high boiling point has a boilingpoint of greater than about 100° C.
 60. The method of claim 48 whereinthe high boiling point solvent comprises ethyl lactate.
 61. The methodof claim 48 wherein the high boiling point solvent is selected from thegroup consisting of methyl lactate, ethyl lactate, isopropyl lactate,ethylene glycol, polyethylene glycol, propylene glycol, dimethylformamide, tetrahydrogeraniol, 1-butanol, 1-pentanol, 1-hexanol,1-octanol, 3-methyl-3-pentanol, dimethyl-3-octanol, 3-methoxy-1-butanol,1,2-butanediol, 1,4-butanediol, 1,3-hexanediol, water and combinationsthereof.
 62. The method of claim 48 wherein the low boiling pointsolvent and the high boiling point solvent are present at a ratio ofabout 1:1.
 63. The method of claim 55 wherein the low boiling pointsolvent and the high boiling point solvent are present at a ratio ofabout 1:1.